Cell membrane proteins are essential components of the cell membrane, which surrounds and protects the cell. These proteins play various roles, including acting as channels or transporters that help move substances in and out of the cell. They can also serve as receptors, allowing the cell to communicate with its environment by responding to signals from other cells or molecules. There are two main types of cell membrane proteins: integral proteins, which are embedded within the membrane, and peripheral proteins, which are attached to the surface. Together, these proteins contribute to the membrane's structure and function, maintaining the cell's integrity and facilitating important biological processes.